This invention relates to automotive air conditioners, and in particular to an improved evaporative-cooling type automotive air conditioner.
Evaporative-cooling is well-suited for air-conditioning in warm and dry climates, and has been applied to automotive air conditioner designs. U.S. Pat. No. 4,953,831 to Albrecht, U.S. Pat. No. 2,767,638 to Davis, U.S. Pat. No. 2,453,018 to Kercheval, U.S. Pat. No. 2,435,798 to Rice, et al, and U.S. Pat. No. 2,230,020 to Webster exemplify several such designs. Known automotive air conditioners which employ evaporative cooling have shortcomings which limit their utility and marketability, however. First, evaporative-cooling air conditioners are a form of direct contact heat exchanger, and must incorporate some means for contacting the warm incoming air directly with a liquid, usually water. The direct contact of the air and water may achieved by dispersing the water on an high-surface area member such as a mat which simultaneously provides the required high surface area and low resistance to flow of the incoming air. Efficient operation of the air conditioner requires that the mat present the largest profile to the incoming air, and that the entire mat is wetted top to bottom. This, combined with the fact that the water reservoir is most conveniently and economically located in the bottom of the air conditioner, means that water must somehow be transferred upwardly from the reservoir to the upper portions of the mat. The prior art teaches that the transfer of water to the mat is best be achieved by use of a pump, whether electrically driven as taught by Albrecht, hand-driven as taught by Kercheval, or mechanically driven as taught by Rice, et al. The prior art also teaches that a mat (Webster) or a water splashing device (Davis) can be rotated through the water reservoir to deliver water the mat. In each instance, the solutions taught in the prior art require moving parts and associated drive mechanisms, which add complexity and cost to the design. The second shortcoming of known designs is that each utilizes a multipart housing which also adds to manufacturing complexity and cost. The multi-part housings of the prior art must be finally assembled as a separate step after assembly and installation of the inner workings. Of equal or greater detriment is the fact that repair or replacement of internal components of multi-part housing designs requires dissembly of the housing. The device must therefore either be designed as a throwaway, i.e. one which is replaced rather than repaired, or the housing must be assembled utilizing removable fasteners such as nuts and bolts, again adding complexity and cost to the manufacture.
For each of these reasons a need remains for an improved air cooler which overcomes the shortcomings of the prior art.